PRINCETON — Council tonight unanimously approved a developer’s agreement for the redevelopment of the Witherspoon Street hospital site, but the agreement calls for additional soil testing and the developer says it won’t comply.

AvalonBay proposes to turn the former University Medical Center site into 280 residential rental units for moderate, low-income and very low-income families, but environmental concerns have prompted additional caution from the town council.

The governing body said it was disappointed with AvalonBay representatives for their refusal to comply with more tests.

“What has pushed it for me here is if Avalon came to table and said, ‘We don’t have to do this, but we’re going to do it.’ I don’t know if it’s a cost factor, but when I have children at Community Park Elementary School ask me if they’re going to be safe when the hospital comes down, I have no choice but to back our consultant’s recommendations 100 percent,” Councilman Lance Liverman said.

Ira Whitman of Cranbury, an independent expert council hired, gave council a follow-up report tonight, elaborating on recommendations he gave last month.

Those included a detailed eight-item list of issues that should be addressed, particularly the excavation of four active and two inactive underground storage tanks at the site, asbestos remediation and lead paint removal.

But AvalonBay attorney Robert Kasuba said the developer will only comply with the less comprehensive recommendations Whitman gave last month.

Council was cautious last month, it said, by not accepting the developer’s agreement in its previous form, and instead asking Whitman to further assess the environmental issues related to the project.

The new agreement is “pretty similar to what I recommended at the March 10 meeting, but the scope of the chemical analysis is somewhat broadened from when I was here four weeks ago,” Whitman said tonight.

Whitman recommended more comprehensive soil testing around areas where medical waste incinerators operated at the site and suggested the concrete AvalonBay plans to crush and reuse be sampled for PCBs and heavy metals.

During the public comment session of the meeting, construction workers and residents supported more testing on site.

“Citizens’ lives are at risk here,” said resident Paul Driscoll. “This is our one chance to get it right.”

Whitman recommended AvalonBay conduct additional soil testing prior to and during the demolition for cadmium, mercury, dioxins and other substances.

He also suggested three more air monitors be installed on site, rather than the one AvalonBay originally proposed.

Even though council accepted the developer’s agreement 6-0, the final demolition plan still needs to be approved by municipal staff, though it’s part of the developer’s agreement.

Residents are worried about the scale and impact of the project, and in January produced evidence of an incinerator once located at the hospital site by doing their own research.

Princeton resident Areta Pawlynsky produce additional documentation last month, revealing a second incinerator operated at the hospital more than two decades before the one constructed in the 1960s.

Whitman’s report tonight accounted for that incinerator, he said.

“One or more medical waste incinerators operated at the Princeton Hospital until approximately 1990,” Whitman’s report said. “I have considered the possibility that some materials that were intended to be incinerated were mishandled and were separated from the waste stream into the incinerator.”

Resident Julie Roth said tonight she was worried about toxic chemicals contaminating the area.

“I’m the mother of three children, and I’m concerned about the many young children that live near the site,” Roth said. “The value of human life is infinite and far outweighs financial profits. Instead of the tone of cross-examination, I wanted to hear reassurance about health and safety of the people.”